In recent years, a wireless communication system which covers a wide area such as a cellular network or a WiMAX (IEEE802.16) is developed. A system including, for example, a Femto Cell which is a wireless communication area narrower than a macro base station, and such a wireless communication area of the base station (macro base station) in the wireless communication system is developed. A Femto Cell system cancels an unfeeling area of radio waves caused when only the macro base station is installed, and expands the wireless communication area more. In the Femto Cell system, a small Femto base station is installed in a house, such as a member's house and a building.
To reduce the interference which an electromagnetic wave by communication between the Femto base station and the wireless terminal gives to surroundings, there is known a technique that an idle period in which the Femto base station does not transmit a wireless signal temporarily is set (See P802. 16m/D2 October 2009).